Co-infections are common in childhood community acquired pneumonia (CAP). However, their etiological pattern and clinical impact remains inconclusive. Eight hundred forty-six consecutive children with CAP were evaluated prospectively for the presence of viral and bacterial pathogens. Nasopharyngeal aspirates were examined by direct immunofluorescence assay or polymerase chain reaction (PCR) for viruses. PCR of nasopharyngeal aspirates and enzyme-linked immunosorbent assays were performed to detect M. pneumoniae. Bacteria was detected in blood, bronchoalveolar lavage specimen, or pleural fluid by culture. Causative pathogen was identified in 70.1% (593 of 846) of the patients. The most commonly detected pathogens were respiratory syncytial virus (RSV) (22.9%), human rhinovirus (HRV) (22.1%), M. pneumoniae (15.8%). Coinfection was identified in 34.6% (293 of 846) of the patients. The majority of these (209 [71.3%] of 293) were mixed viral-bacterial infections. Age < 6 months (odds ratio: 2.1; 95% confidence interval: 1.2–3.3) and admission of PICU (odds ratio: 12.5; 95% confidence interval: 1.6–97.4) were associated with mix infection. Patients with mix infection had a higher rate of PICU admission. The high mix infection burden in childhood CAP underscores a need for the enhancement of sensitive, inexpensive, and rapid diagnostics to accurately identify pneumonia pathogens.

To analyze the clinical characteristics of corticosteroid-resistant refractory Mycoplasma pneumoniae pneumonia (RMPP) and explore the related factors that predict corticosteroid-resistant RMPP. Retrospective analysis of 183 children with RMPP in our hospital admitted between January 1, 2012, and December 31, 2014 was performed. Of the 183 RMPP cases, 36 (19.7%) were corticosteroid-resistant RMPP cases. Corticosteroid-resistant RMPP cases had a longer duration of fever and hospitalization compared with corticosteroid-sensitive RMPP cases (P < 0.05). The radiographic findings of 123 (83.7%) cases of corticosteroid-sensitive RMPP apparently resolved after one week of corticosteroid treatment compared with 4 (11.1%) corticosteroid-resistant RMPP cases that had apparently resolution (P < 0.01). Twenty-four (75%) corticosteroid-resistant RMPP patients who received bronchoscopy had mucus plug formation while none of the corticosteroid-sensitive RMPP patients had mucus plug formation (P < 0.05). Multiple logistic regression analysis showed that duration of fever ≥11 days, percentage of lymphocytes ≤32%, CRP ≥48.73 mg/L and LDH ≥ 545.7 U/L were significant predictors of corticosteroid-resistant RMPP. Patients with corticosteroid-resistant RMPP had more severe presentations and more serious radiological findings. Clinicians might use the parameters of duration of fever, CRP, LDH and proportion of lymphocytes to identify children at higher risk of corticosteroid-resistant RMPP.

To assess the impact of human bocavirus (HBoV) virus load on epidemiologic and clinical characteristics in children with lower respiratory tract infection (LRTI). Clinical records of a total of 654 patients with HBoV infection during January 2013 and December 2014 were retrospectively reviewed. Patients with high HBoV virus load infection had a similar age distribution with the total HBoV infection, which had a peak age group of 6–24 months. Patients with high virus load are significantly younger (P < 0.01) than those with low load. The patients who had wheeze and tachypnea/dyspnea at presentation were more strongly affiliated with the patients with high virus load (both P < 0.01). Co-infection was found significantly more frequently among patients with low virus load than those with high virus load (57.0% vs 38.9%; P < 0.01). High virus load was a significant predictor of severe LRTI (P < 0.05). HBoV infections are found in an important proportion of the hospitalized children with respiratory illnesses (8.85% in our series). A high HBoV virus load could be an etiologic agent for LRTI, which may lead to more severe lower respiratory tract symptom and severe disease.

Background: We aimed to find the relationship between the clinical characteristics and mucus plug formation and developed models to predict mucus plug formation in refractory Mycoplasma pneumoniae pneumonia (RMPP) infection. Methods: RMPP patients treated with bronchoscopy were retrospectively enrolled in the study between November 2011 and November 2015. Multivariate logistic regression was performed to identify independent predictors of mucus plug formation. Results: Of the 173 RMPP patients enrolled, the mucus plug group accounted for 82 (47.4%) cases. Multivariate logistic regression analysis identified age, fever duration, C-reactive protein (CRP) and lactic dehydrogenase (LDH) as independent risk factors for mucus plug. We assigned one point for age, length of fever and CRP and two points for LDH. Using this predicted score, we identified patients with mucus plug with 71.8% sensitivity and 78.9% specificity. Conclusions: Our predictive models based on demographic and laboratory variables accurately predicted mucus plug formation in initial treatment of patients with RMPP.

Objective: This study examines the epidemiology of Mycoplasma pneumoniae (M. pneumoniae) infections among children in Suzhou, China, during various pandemic phases. The goal is to discern evolving epidemic trends and to furnish robust evidence for clinical diagnosis and treatment.Methods: From January 1, 2016, to December 31, 2023, 113,625 consecutive patients with respiratory infections from three hospitals in Suzhou, China (Children’s Hospital of Soochow University, Children’s Hospital of Wujiang District, and Affiliated Suzhou Hospital of Nanjing University Medical School), were retrospectively enrolled in a surveillance study. Additionally, in 2023, children hospitalized with M. pneumoniae pneumonia at the Children’s Hospital of Soochow University were tested for genotype (P1 gene typing, SNP genotyping) and macrolide resistance in their bronchoalveolar lavage fluid.Results: From 2016 to 2023, the M. pneumoniae positive detection rate among pediatric respiratory infections fell from a pre-pandemic 21.1% to pandemic lows, then surged to 45.3% post-pandemic. Before the pandemic, peak M. pneumoniae infection rates occurred in summer, followed by autumn. Post-pandemic, the highest peak rates were in autumn. Peak M. pneumoniae detection rates occurred in 2019 and 2023, with a notable increase in children aged 6 and older in 2023. In this study, 200 M. pneumoniae-positive bronchoalveolar lavage fluid (BALF) cases in 2023 were randomly selected and analyzed for P1 genotype and SNP genotype. Among 156 cases, 81.4% were P1 genotype and 18.6% were P2 genotype. The proportion of severe M. pneumoniae pneumonia with the P1 type was significantly higher than that with the P2 type (p < 0.05). Of the 192 samples analyzed, 11 SNP genotypes were identified, with SNP-27 predominating (36.5%), followed by SNP-0 (21.4%), SNP-11 (18.8%), and SNP-34 (17.7%). Of the 192 BALF specimens, 97.3% exhibited macrolide resistance mutations, with A2063G mutations at 96.17%. The mutation rates for the 23S rRNA 2064 and 2,617 were 1.6 and 1.0%, respectively.Conclusion: Post-COVID-19 in Suzhou, China, M. pneumoniae infection patterns shifted significantly, with initial NPIs-induced declines followed by a sharp rise in cases, especially impacting school-age children. This trend underscores the importance of ongoing epidemiological surveillance and the development of strategic public health responses.

Background: Bronchiolitis is a clinical syndrome commonly encountered in practice, particularly among infants and young children. To investigate the prevalence of pathogens in hospitalized children with bronchiolitis and study the clinical characteristics of bronchiolitis with or without coinfections. Methods: We investigated the respiratory specimens and clinical data of 1012 children with bronchiolitis who were treated at the Children’s Hospital of Soochow University between November 2011 and December 2018. The nasopharyngeal aspirates were examined to detect viruses by direct immunofluorescence assay or polymerase chain reaction (PCR). Mycoplasma pneumoniae (MP) was tested by PCR and enzyme-linked immunosorbent assay. Results: Of the 1134 children less than 2 years with bronchiolitis, 122 were excluded by exclusion criteria. Causative pathogen was detected in 83.2% (842 of 1012). The majority of these (614 [72.9%] of 842) were single virus infection. The most common pathogens detected were respiratory syncytial virus (RSV) (44.4%), MP (15.6%), and human rhinovirus (HRV) (14.4%). Coinfection was identified in 13.5% (137 of 1012) of the patients. Coinfection included mixed virus infection and virus infection with MP infection. Children with single virus infection had a higher rate of oxygen therapy compared with single MP infection. Conclusions: The most common pathogen detected in children with bronchiolitis is RSV, followed by MP and HRV. Coinfection leads to a longer period of illness, increased severity of the symptoms and increased risk of hypoxemia.